G1 Homing questions

  • This line, G1 Z-5 F6000 S2 , lowers my bed away from the nozzle for X and Y homing.
    My Z axis is set up from 0 to 350mm, with 0 being bed raised to max near nozzle and 350 being bed lowered to max, farthest from nozzle.
    The Z direction is set by this line, M569 P2 S0.

    Q1. Why is the Z move command G1 Z-5 to move downward? Should it not be Z+5, eg if Z is at +3, the relative move +5 should lower bed to +8?

    Q2. X and Y home properly, bumping endstop, move back 5mm, bump again slowly and stay at zero. If I add a "G1-5" to back off the endstop after the second bump, is axis home set at the endstop bump position or at the final -5mm position? Code example with second move away from endstop:

    G91 ; relative positioning
    G1 Z5 F6000 S2 ; lift Z relative to current position
    G1 S1 X310 F1800 ; move quickly to X axis endstop and stop there (first pass)
    G1 X-5 F6000 ; go back a few mm
    G1 S1 X310 F360 ; move slowly to X axis endstop once more (second pass)
    G1 Z-5 F6000 S2 ; lower Z again
    G90 ; absolute positioning

  • q1) the configurator normally does generate with z5. you might have set a parameter for the opposite direction on initial config.

    q2) that depends on your M208 minima settings. it is set to the minima position.

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